1. Field of the Invention
The disclosed invention relates to a method and system for stabilization and support of equipment, specifically wind turbine blades when they are removed from a wind turbine for cleaning or maintenance tasks.
2. Description of Related Art
Wind turbines are rapidly gaining respect as a viable source of energy needs and consequently, the production and installation of these structures is exploding. Accompanying their growth is a host of challenges including the need to develop better and easier ways to perform cleaning and maintenance tasks.
The traditional wind turbine is a three bladed turbine mounted on a tower. Horizontal-axis wind turbines (HAWT) are common and typically comprise a main rotor shaft and electrical generator at the top of a tower. Larger turbines generally use a wind sensor coupled with a servo motor and often a gearbox to speed the blade rotation to a suitable speed for an electrical generator.
On commercial wind turbines, towers are tall, at times nearly 90 meters. Turbine blades are extremely large and stiff to prevent the blades from being pushed into the tower by high winds. Cleaning and maintenance to the blades, hub, axles, bearings, and or the generator, motor or gearbox is critical to ensure efficient performance. The most common method of accessing the blades for these routine tasks is to remove the entire bladed turbine from the tower. Due to the height of the tower, coupled with the cumbersome size and rigidity of the turbine and blades, removal and maintenance becomes a challenging feat, requiring tall and expensive cranes and skilled operators. Once the turbine and blades are removed from the tower they are typically lowered to the ground for the cleaning or maintenance tasks. The turbine sits on the ground, however the design of the overall structure results in the blades being suspended in the air rather than touching the ground. In this position the blades, with their extreme length unsupported, are extremely vulnerable to catching and twisting in the wind, torquing, bending or breaking.
Workers, in a desperate attempt to support and stabilize the blades during cleaning or maintenance tasks, are resorting to hay bales or huge foam blocks on which to set the blades. These methods come with significant inherent disadvantages. Hay is an impractical solution because often the wind turbines are located on ranches and farms where range animals are present. Cows, horses, goats, sheep and other animals then mill about the blades in an attempt to eat the hay or, in some cases, even the foam blocks. This situation creates a nuisance and a danger to the contractors. The hay bales are large and difficult to move. The hay itself is rough and scratchy and can damage the blades. Foam blocks weigh less than hay but they are still bulky and must be transported on large trailers from site to site, resulting in unnecessary equipment and fuel expense, certainly contradicting the purpose of creating wind energy.
There is a need for quick and easy system to support and stabilize wind turbine blades during maintenance efforts. The solution must be relatively inexpensive, lightweight and small for purposes of packaging and transport, but yet capable of supporting and stabilizing great weight and large bulk.